Biomass characterization of wild and cultivated cardoon accessions and estimation of potential biofuels production

Abstract

Cardoon is considered an interesting raw material to obtain second-generation biofuels, due to its perennial culture condition and its rare use as food. In addition, cardoon, being a rustic species, requires few inputs and has fast growth and high lignocellulosic biomass production. However, despite its large genetic variability worldwide, both cardoon botanical varieties were subject only to few (cultivated cardoon)/zero (wild cardoon) breeding programs. The aims of this study were (I) to characterize biomass quality and quantity of genotypes of wild and cultivated cardoon in order to produce different types of biofuels and (II) to identify the most promising accessions to be included in breeding programs for bioenergy characteristics or to be incorporated in the local agro-productive system. The performance of twelve Cynara cardunculus L. accessions (six cultivated cardoons and six wild cardoons) was compared through biometric, chemical, and energetic characteristics. Moreover, the potential bioethanol and biomethane yields and the energy potentially generated from direct combustion were calculated for each botanical variety. Significant differences were found between botanical varieties for several biometric traits, but not in chemical traits except for ash content. Results indicate that cardoon biomass, especially cultivated cardoon, has characteristics that make this species a promising candidate to be grown for energy purposes under very low crop inputs in the local edapho-climatic conditions. In addition, our screening identified an accession that stands out based on yield, biomass composition, and potential to produce different types of biofuels/bioenergy.